Riffler for cellulose stock



Patented res. 5,1946

2,394,378 amen FOR CELLULOSE STOCK William E. Henry, Hopewell, Va.,assignor to Hercules Powder Company, Wilmington, DeL, a corporation ofDelaware Application August 7, 1943, Serial No. 497,789

4 Claims. (or. 92-28) This invention relates to the refining of cellulose materials and more particularly to rifliers of the trough typewhich are used in conjunction with other processing equipment in the artof paper making.

Heretofore, a rifiler in the form of'a rifile trough, that is, a shallowwooden sluice equipped with a set of baflles all along the bottom andsometimes provided with a felt lining on the bottom, has been utilizedto catch and retain the solid impurities in the paper stock. Therifiler, generally, is on a level, without any incline, so that thecurrent is leisurely, being produced by the pump that draws the stockfrom the rifiler. In this trough the various heavy impurities that maybe in the stock, such as particles of sand. metallic objects and thelike, sink to the bottom and are held by the bailies or the felt or acombination of these. The capacity of the rifller should be sufiiclentto take care of the output of the digesters, or that portion of thedigester output devoted to paper making and the length is governedchiefly by the amount of space able to be devoted to it, the longer thebetter.

The stock from the rifller is either pumped or gravitates to subsequentprocessing apparatus, such as diaphragm screens or other apparatusdepending upon the particular process being employed. The =riiiler mustbe cleaned from, time to time to remove the entrapped solid impurities.The prior art riiiler devices are very difficult to clean andexceedingly expensive to maintain.

This is particularly so when it is necessary to use felt to catch andretain the solid impurities,

as the. felt mats are expensive to replace. How-' ever, a felt mat onthe bottom of the rifiler still remains as the most effective means inthe prior art devices to retain the solid impurities in the stock,particularl when it is necessary that the stock as discharged from theriflier be substantially free of solid impurities. It is, therefore, theprincipal object of this invention to improve rlmers of this generaltype. Another object of this invention is to provide an improved riflletrough in which the solid impurities in the stock are more effectivelyremoved, and the cleaning of the trough may be effectively andexpeditiously performed. Other objects of the invention will appearhereinafter, the novel features and combinations being set forth in theappended claims. .7

Generally described, the present invention comprises a riflle assemblyhaving in combination supported foraminous members with a plurality ofsettling areas disposed therebeneath and a plurality of overflowsections disposed thereabove, said assembly being constructed in unitsand each unit adapted to be removed to facilitate and expedite cleaningof the settling areas.

A preferred embodiment of the invention has been chosen for purposes ofillustration and description and is shown in the accompanying drawingforming a part of the specification wherein reference symbols refer tolike parts wherever they occur: Fig. 1 is a fragmentary plan view of oneform of apparatus for the em bodiment of the invention; Fig. 2 is afragmentary sectional view taken along the section 2-2 of Fig. 1; andFig. 3 is a transverse sectional view of the apparatus shown in Fig. 1.

In Figs. 1, 2 and 3, a sluice I with sides 3 and 5 and a bottom I isprovided with a liquid impervious metallic lining 9. A perforated screenll, disposed along the bottom of sluice I, has a plurality of supportingangle irons l3 rigidly secured to the bottom thereof. The screen II alsohas an angle iron l5 rigidly secured to the top thereof. A plurality ofhinges ll are rigidly secured through the screen I I to the angle ironsl3 and to the side 5 of the sluice I. A longitudinal member is isrigidly secured to the screen II which member is in turn provided with ahandle 2 l. The handle 2| in conjunction with the hinges ll providesmeans for lifting the perforated screen II with its affixed members l3and I5 and disposing the assembly to facilitate cleaning, as indicatedby 23 in Fig. 3. A look member 25 for each section of the screen II ispivotally secured to the side 3 of the sluice i. This lock member servesto maintain the screen ll firmly in posltion and the pivotal connectionof the lock member 25 permits the disengagement of said memher with thescreen structure so that the screen structure may be placed in theposition as indicated-by 23., It is, of course, understood that arifiler is composed of a number of the above described units disposed ina sluice of considerable length, the length depending upon theparticular processing problems involved, such as, the desired purity ofthe stock, the space available for the rifiinetc.

An example of the operation of the invention is given for removing solidimpurities from paper stock. The stock is leisurely floated into thesluice I, thereupon overflowing the members l5. This leisurely now ofthe stock and the obstruction caused by the members l5 create in effecta stilling pool and the small solid impurities hav-- ing a densitygreater than the stock migrate down through the perforated screen. IIand are entrapped within settling basins formed between able period ofuse the large particles of solid imsurface of the perforated screen H,the screen is then raised to the position indicated by 23 in Fig. 3, andthe small particles of solid impurities are flushed away with wash wateror removed by other suitable means;

It. is evident that there are numerous factors which will influenceconditions for the most satisfactory operation of the invention, theactual limits of which cannot be established except by detailed study ofeach set of materials being processed and the intermediate and finishedproducts involved. However, the rifiler device of the present inventionhas been found highly effective in conjunction with the treatment ofcellulose materials and more particularly cotton linters. In thisparticular adaptation of the invention the perforated screen consistedof -inch copper sheet perforated with -inch diameter holes on A -inchcenters. The angles were one inch brass angles and were welded to theperforated sheet.

The perforated sheet was approximately three feet wide and eight feetlong, the width conformpurities are removed byhand from the upperforaminous member; and means for integrally removing said unit from itsfunctioning position to a second position whereby cleaning of the sluicetrough is facilitated.

2. A rifiler for use in treating a stock of cellulose materials havingin combination a sluice.

trough and a plurality 'of riille units disposed therein; the sluicetrough having water impervious sides and bottom members; and each of theriille units comprising a substantially plane foraminous screen memberprovided with a multiplicity of perforations in spaced relationship tothe bottom of said trough; a plurality of sup porting and spacingmembers securely a'ifixed to I 3. A riffier for use in treating a stockof cellulose materials having in combination a sluice trough and aplurality of rifile units disposed therein; the sluice trough havingwater impering'to the width of the sluice, and the length I being suchthat the units could be easily lifted for cleaning purposes.

The advantages of the present invention reside in a riflier whichprovides a more efficient method of separating solid impurities frompaper stock than has heretofore been attained and in addition provides amore expedient method for cleaning a rifller. This results in a minimumtime of plant shutdown and an increase in overall plant production. Astill further advantage resides in the economies of maintenance, as theefficiency of ariffler in accordance with the present invention is suchthat felt pads and like materials are unnecessary and the attendant highcleaning costs and replacement costs of these materials are eliminated.

What I claim and desire to protect by Letters Patent is:

1. A rifller for use in treating a stock of cellulose materials havingin combination a sluice trough and a plurality of riffle units disposedtherein; the'sluice trough having water impervious sides and bottommembers; and each of the riffie units comprising a substantially planeforaminous screen member provided with a multiplicity of perforations inspaced relationship to the bottom of said trough; a plurality ofsupporting and spacing members securely aifixed'to the I bottom of theforaminous member transversely of the trough adapted to maintain saidspaced relationship and provide stilling areas between said supportingmembers; at least one overflow member of substantial height disposedabove said vious sides and bottom members; and each of the rifile unitscomprising a substantially plane foraminous screen member provided witha multiplicity of perforations in spaced relationship to the bottom ofsaid trough; said foraminous member being hingedly secured to a side ofthe said trough and adapted to be lifted from its position in spacedrelationship to the bottom of the trough to a second position injuxtaposition to the side of said trough; a plurality of supporting andspacing members securely affixed to the bottom of the foraminous membertransversely of the trough adapted to maintain said spaced relationshipand provide at least one stilling area between said supporting members;and at least one overflow member of substantial height aflixed I to thetop of the'foraminous member adapted to provide an overflow sectiontransversely of the trough.

4. A rifiier for use in treating a stock of cellulose materials havingin combination a sluice trough and a plurality of riflle units disposedtherein; the sluice trough having waterimpervious sides and bottommembers; and each of the riflie units comprising a substantially planeforaminous screen member provided with a multiplicity of perforations inspaced relationship to the bottom of said trough; a plurality ofsupporting and spacing members of substantial height securely affixed tothe bottom of the foraminous member transversely of the trough and inlower-edge proximity thereto and providing stilling areas betweenadjacent pairs of said supporting members; at least one overflow memberof substantial height afiixed to and disposed above the foraminousmember transversely of the trough; and means for integrally removingsaid unit from its functioning position to a second position wherebycleaning of the sluice trough is facilitated.

WILLIAM E. HENRY.

